The present invention relates to a process for producing a polyether which has its high degree of polymerization and which is useful in the field of cosmetics and in the field of chemical products and to a novel polyether.
Up to now, in the ring-opening polymerization of a substituted epoxide, a molecular weight of the resultant product has been much decreased in general owing to chain transfer originated from extraction of an atom from the substituent. With respect to propylene oxide and an epihalohydrin, the decrease in the polymerizability is not notably decreased by way of exception. The molecular weight may reach millions by selecting a catalyst. However, with the other substituted epoxide, a polyether having its high degree of polymerization could not be obtained in good yield. This is notably observed in particular in the case of an epoxide having a bulky substituent, such as an epoxide having a long chain alkyl group or a silicone chain as a substituent and an epoxide having a highly electron-attractive fluoroalkyl chain as a substituent. That is, these could not be polymerized in good yield even by using a coordinated anionic catalyst, which is deemed in general to have a high activity as a catalyst for polymerization of epoxide, such as a catalyst comprising organoaluminum-water-acetyl acetone and a catalyst comprising organozinc-water. Further, since an epoxide having a highly reactive hydroxyl group such as glycidol deactivates a coordinated anionic catalyst, it could not be polymerized in high degree without protecting the hydroxyl group.
In recent years, examples of using a composition containing a rare earth metal compound as a catalyst for polymerization of ethylene oxide, propylene oxide or epichlorohydrin are seen in, for example, {circle around (1)} Inorg. Chim. Acta, vol. 155, 263 (1989), {circle around (2)} Polymer J., vol. 22, 326 (1990) and {circle around (3)} Macromol. Chem. Phys., vol. 196, 2417 (1995). All of these tried to polymerize ethylene oxide, propylene oxide or epichlorohydrin. It is described that polyethyleneoxide having its number average molecular weight of 2,850,000 is obtained in {circle around (1)}, polyepichlorohydrin having its viscosity average molecular weight (deemed to obtain a value being close to a weight average molecular weight) of 790,000 to 1,650,000 in {circle around (2)} and polypropylene oxide having its number average molecular weight of 70,000 to 980,000 (weight average molecular weight of 120,000 to 3,770,000) in {circle around (3)}. However, the degree of polymerization thereof is approximately the same as that of a conventional coordinated anionic catalyst. In consideration of the fact that when a substituted epoxide other than propylene oxide and epihalohydrin (hereinafter referred to as the substituted epoxide) was polymerized using these conventional catalysts, a polyether having its high degree of polymerization could not be obtained. The rare earth metal compound showing approximately the same performance as the conventional catalyst were not expected to be a useful catalyst in order to obtain a polyether having its high degree of polymerization from the substituted epoxide.
The present invention is aimed to provide a process for efficiently obtaining a polyether having its high degree of polymerization which comprises easily polymerizing a substituted epoxide, other than propylene oxide and epihalohydrin, being hardly or not able to be polymerized in high degree, up to now.
The present invention provides a process for producing a polyether which comprises ring-opening-polymerizing a substituted epoxide, except for propylene oxide and epihalohydrin, in the presence of a rare earth metal compound represented by the formula (I) and a reducing compound and provides a novel polyether obtained thereby: 
wherein
M represents a rare earth element selected from Sc, Y and lanthanide, and
L1, L2 and L3 are same as or different from each other and each of them represents an oxygen-binding ligand.
(1) Substituted Epoxide
The substituted epoxide of the present invention means ethylene oxide having a substituent, and examples thereof are as follows.
(1-1) Compounds represented by the formula (II): 
wherein
R1 represents a hydrocarbon group which may have a substituent and which has 1 to 50 carbon atoms, represents an acyl group having 1 to 30 carbon atoms, represents an alkyl sulfonyl group having 1 to 30 carbon atoms or an aryl sulfonyl group having 6 to 30 carbon atoms or represents a group represented by xe2x80x94(AO)nxe2x80x94R2.
Here, R represents a hydrocarbon group, a fluoroalkyl group or a fluoroalkenyl group, which may have a substituent and which has 1 to 30 carbon atoms, or a fluoroaryl group, which may have a substituent and which has 6 to 30 carbon atoms, or represents a siloxysilyl group having 1 to 500 silicon atoms. A represents an alkylene group having 2 or 3 carbon atoms. n represents a number selected from 1 to 1,000.
Here, preferable examples of the hydrocarbon groups which may have a substituent with respect of R1 include an alkyl group or alkenyl group having 1 to 42 carbon atoms and an aryl group having 6 to 42 carbon atoms. Examples of the substituent of the hydrocarbon group include a hydroxy group, an alkoxy group (having 1 to 30 carbon atoms), an amino group (a dimethyl amino group, a diethyl amino group or the like), an amide group, a trialkyl ammonium group, a dialkyl ammonium group, an alkyl ammonium group, an ammonium group, an ester group, a carboxyl group, an acyl group (having 1 to 30 carbon atoms), a silyl group, a siloxy group, a nitro group, an aryl sulfonyl group, a cyano group, a phosphonyl group (hereinafter referred to as xe2x80x9cthe substituent of the present inventionxe2x80x9d). An alkyl group in this case has 1 to 30 carbon atoms.
A preferable example of the acyl group may be an acyl group having 4 to 22 carbon atoms in total. In this acyl group, a hydrocarbon group may be an alkenyl group. Further, R1 may be a sulfonyl group having 1 to 30 carbon atoms. A specific example thereof may be a benzenesulfonyl group, a toluenesulfonyl group or a nitrobenzenesulfonyl group.
(1-2) Compounds represented by the formula (III). 
Wherein
R3 represents a fluoroalkyl group or fluoroal kenyl group, which may have a substituent and which has 1 to 30 carbon atoms, or a fluoroaryl group which may have a substituent and which has 6 to 30 carbon atoms, and
a represents a number selected from 0 to 20.
a is preferably a number selected from 0 to 4. The R3 group is preferably exemplified as trifluoromethyl, pentafluoroethyl, nonafluorobutyl, perfluorohexyl, perfluorooctyl, perfluorododecyl, perfluoro-3-methylbutyl, perfluoro-5-methylhexyl, perfluoro-7-methyloctyl, perfluoro-9-methyldecyl, 1,1-difluoromethyl, 1,1,2,2-tetrafluoroethyl, 4H-octafluorobutyl, 5H-decafluoropentyl, 6H-dodecafluorohexyl, 8H-hexadecafluorooctyl, 10H-icosafluorodecyl, trifluoroethenyl or perfluorophenyl. A preferable example of the substituent of R3 may preferably be xe2x80x9cthe substituent of the present inventionxe2x80x9d mentioned above.
In the substituted epoxide (III), a compound having a=0 and the R3 group is a perfluoro group having 1 to 30 carbon atoms is more preferable.
(1-3) Compounds represented by the formula (IV). 
Wherein
all of plural R4s are same as or different from each other, and each of plural R4s represents a hydrocarbon group which may have a substituent and which has 1 to 30 carbon atoms or represents a siloxy group having 1 to 200 silicon atoms,
G represents an alkylene group, which may have a substituent and which has 1 to 20 carbon atoms, or an arylene group
b represents a number selected from 1 to 500 as an average value of plural numbers or represents an integer of 1 to 20 as a single number, and
p represents a number selected from 0 and 1.
Here, when the R4 group is a hydrocarbon group which may have a substituent and which has 1 to 30 carbon atoms, examples of the substituent include an ester group, an amide group, an amino group, a hydroxy group and a polyoxyalkylene group.
Preferable examples of the R4 group include a hydrocarbon group having 1 to 10 carbon atoms and a linear or branched siloxy group having 1 to 100 silicon atoms. More preferable examples include amethyl group, a butyl group, a vinyl group anda phenyl group.
When the R4 group is a siloxy group, a group to combine with a silicon atom in the siloxy group may be a methyl group, a butyl group, a vinyl group or a phenyl group.
In the (G)p group, it may be preferably exemplified that p=0 or p=1 and the G group is a alkylene group such as methylene group, ethylene group and trimethylene group, phenylene group or the like. In view of easiness of the synthesis, the methylene group or the trimethylene group is especially preferable.
In the formula (IV), b represents a chain length of the siloxy group. The chain length may have a distribution or may be a single chain length. Especially, when b is 1 to 20, it is possible that a polyether having a siloxy chain comprising its single chain length is selectively obtained.
Properties of the polyether of the present invention, such as an appearance, an elastic modulus, a solubility in a solvent, vary greatly depending on the value of b. The smaller value of b is, the more remarkably this phenomenon is observed. Further, the smaller the value ofb is, the higher ahydrophilic property of the polyether is.
(1-4) Glycidol.
With respect to the substituted epoxide shown in (1-1) to (1-4), two or more of these can be co-polymerized. Further, one or more of these and other epoxy compounds such as ethylene oxide, propylene oxide and/or epichlorohydrin can be co-polymerized. Still further, one or more of these and an anionic-polymerizable monomer can be co-polymerized. Examples of such a monomer include styrene, vinylnaphthalene, 1,3-butadiene, isoprene, 2,3-dimethyl-1,3-butadiene, 1,3-pentadiene, 1,3-cyclohexadiene, vinyl pyridine, (meth)acrylic acid esters such as methyl methacrylate, episulfides, 4-, 6- or 7-membered lactones, 5- or 6-membered carbonates, lactams and cyclic silicones. More preferable monomer is styrene, 1,3-butadiene, isopreyne, methyl methacrylate, xcex2-lactone and hexamethyl cyclotrisiloxane.
(2) Ring-opening Polymerization of a Substituted Epoxide
In the rare earth metal compound represented by the formula (I), which is used in the present invention, examples of M include Sc, Y, La, Ce, Pr, Nd, Pm, Sm, Eu, Gd, Tb, Dy, Ho, Er, Tm, Yb and Lu. Among them, Sc, Y, La, Nd, Sm, Eu, Gd, Dy, Er, Yb or Lu is preferable in view of the polymerization-activity and the economy.
Further, L1, L2 and L3 are oxygen-binding ligands. Examples thereof can include a methoxy group, an ethoxy group, an n-propoxy group, an i-propoxy group, a butoxy group, an allyloxy group, a methoxyethoxy group, a phenoxy group, a 2-methoxypropoxy group, a trifluoroethoxy group, a 2,4-pentanedionato group (acetyl acetonato group), a trifluoropentanedionato group, a hexafluoropentanedionato group, a 6,6,7,7,8,8,8-heptafluoro-2,2-dimethyl-3,5-octanedionato group, a 2,2,6,6-tetramethyl-3,5-heptanedionato group, a thienoyl trifluoroacetonato group, a furoyl trifluoroacetonato group, a benzoyl acetonato group, a benzoyl trifluoroacetonato group, an acetato group, a trifluoroacetato group, a methyl acetoacetato group, an ethyl acetoacetato group, a methyl (trimethyl)acetyl acetato group, a 1,3-diphenyl-1,3-propanedionato group, a methyl sulfonate group, a trifluoromethyl sulfonate group, a dimethyl carbamate group, a diethyl carbamate group, a nitrite group, a hydroxamate group, and an oxygen-binding chelating agent such as an ethylenediamine tetraacetic acid, a diethylene triaminepentaacetic acid, an ethylenediamine tetrakismethylene sulfonic acid, a hydroxy ethylenediamine triacetic acid, nitrilotriacetic acid, and azomethene H. However, the ligand is not limited by them.
Among them, an i-propoxy group, a 2,4-pentanedionato group (acetyl acetonato group), a trifluoropentanedionato group, a hexafluoropentanedionato group, a 2,2,6,6-tetramethyl-3,5-heptanedionato group, an acetato group or a trifluoroacetato group is preferable in view of the polymerization-activity and the economy.
The rare earth metal compound can easily be synthesized by, for example, the reaction of a halide, oxide, hydroxide or nitrate of the rare earth metal with the above-mentioned oxygen-binding ligand or a precursor compound providing the ligand. Each of them may be used after it is previously synthesized and then purified. On the other hand, it may be used in the polymerization system while mixing the rare earth metal compound and the above-mentioned oxygen-binding ligand or the precursor compound providing the ligand.
Further, the rare earth metal compound can be used by being supported on an appropriate carrier if necessary. The type of the carrier is not particularly limited. Any of inorganic oxide carriers, phyllosilicates such as clayey minerals, activated charcoals, metal chlorides, other inorganic carriers and organic carriers may be used. Moreover, the supporting method is not particularly limited, and a publicly known method can be used at the option.
Moreover, the rare earth metal compound may contain an electron-donating ligand such as tetrahydrofuran, diethyl ether, dimethoxy ethane, tetramethyl ethylenediamine, triethyl phosphine.
The amount for use of the rare earth metal compound can be determined, as required, depending on the polymerizability of the said compound, the polymerizable faculty and the amount for use of the substituted epoxide, the desired degree of polymerization and the total amount of the materials which inhibit polymerization and which are present in the reaction system. In the case of the polymerization reaction in a highly purified polymerization system, it is preferably between 0.000001 and 10 equivalents, more preferably between 0.0001 and 1 equivalent, further preferably between 0.0002 and 0.5 equivalent based on the number of moles of the substituted epoxide. When it is at least 0.000001 equivalent, a high polymerization-activity can be obtained. Further, when it is at most 10 equivalents, formation of oligomers (low-molecular polymers) can be inhibited.
The reducing compound used in the present invention may be any compound so long as the compound has a reducibility for reducing the whole or a part of the trivalent rare earth metal compound represented by the formula (I) in order to generate a rare earth metal having quite a high polymerization-activity. Examples thereof for use include (1) an organoaluminum compound such as trimethyl aluminum, triethyl aluminum and triisobutyl aluminum; a two-component catalyst thereof; or a three-component catalyst obtained by adding an alcohol or a chelating compounds thereto; (2) an aluminum trialkoxide; (3) a dialkyl aluminum alkoxide; (4) a dialkyl aluminum hydride; (5) an alkyl aluminum dialkoxide; (6) methylaluminoxane; (7) an organoaluminum sulfate; (8) a two-component catalyst of an organozinc compound such as dimethyl zinc and diethyl zinc with water; or a three-component catalyst obtained by adding an alcohol or a chelating compound thereto; (9) a zinc alkoxide; (10) an organolithium compound such as methyl lithium and butyl lithium; and a mixture of one of them and water; and (11) an organomagnesium compound such as dialkyl magnesiums and Grignard reagent; a mixture of one of them and water; and another organic and inorganic compound having its reducibility. Among them, the above-mentioned catalyst (1), (6), (8) or (11) is preferable because it has the appropriate reducibility.
Each of these reducing compounds may be used after it is previously mixed with the rare earth metal compound and then reacted. On the other hand, it may be used in the polymerization-system while being mixed with the rare earth metal. By the way, when it is used after the previous mixing and reaction, it may be retained and aged at an appropriate temperature in order to use it. This aging operation can further increase the polymerization-activity.
The amount for use of the reducing compound can be determined, as required, depending on the reducibility and the type and the amount for use of the rare earth metal compound. When the reducing compound is a compound containing a metal such as aluminum, zinc, lithium and magnesium, the number of moles of the metal for use is preferably between 0.001 and 200 equivalents, more preferably between 0.01 and 100 equivalents and especially preferably between 0.1 and 50 equivalents as compared with the number of moles for use of the rare earth metal. When it is at least 0.001 equivalent, a high polymerization-activity can be obtained. Further, when it is at most 200 equivalents, formation of oligomers (low-molecular polymers) can be inhibited.
When the present invention is being carried out, it is enough that the substituted epoxide is polymerized using the rare earth metal compound represented by the formula (I) and the reducing compound. The temperature for the polymerization is desirable to be in the range of xe2x88x9278 to 220xc2x0 C., especially xe2x88x9230 to 160xc2x0 C. The polymerization of the substituted epoxide can be carried out in the absence of a solvent, when the substituted epoxide is in a molten state in the range of the temperature for the polymerization. However, it is usually desirable to carried out the polymerization in an inert solvent.
Examples of such a solvent include hydrocarbons such as benzene, toluene, xylene, ethyl benzene, n-pentane, n-hexane, n-heptane, isooctane and cyclohexane; ethers such as diethyl ether, dipropyl ether, dibutyl ether, tetrahydrofuran and dioxane; and halogenated hydrocarbons such as methylene chloride, chloroform and carbon tetrachloride; as well as N,N-dimethyl sulfoxide and a mixture thereof. Usually, it is good that the solvent selected therefrom for polymerization is used after sufficiently dehydration and deaeration.
Further, the polymerization of the substituted epoxide can also be carried out in a gaseous stream of the substituted epoxide, when the substituted epoxide is in a gaseous state in the range of the temperature for the polymerization.
The polymerization reaction of the present invention is desirably carried out under a condition in which oxygen is excluded. It is desirably carried out under an atmosphere of an inert gas such as nitrogen, helium and argon; under a reduced pressure by deaeration; under a condition introduced with vapor of a solvent by deaeration; or in a gaseous stream of the substituted epoxide. The pressure for polymerization is not particularly limited, and it may be any of normal pressure, reduced pressure or pressurization.
The polymerization reaction of the present invention can be carried out by an optional mixing method. The three members, i.e. the substituted epoxide, the rare earth metal compound and the reducing compound, may be mixed at a time and used. To a system being prepared previously and containing one or two members of these, the remaining two or one member may be added.
When the present invention is being carried out, one or more members thereof can be used as the substituted epoxide. Further, each of these can be used in combination with the other epoxy compound, i.e. ethylene oxide, propylene oxide epichlorohydrin and/or the like. When two or more substituted epoxy compounds are used, these may be mixed at a time and used. These can be introduced into the polymerization system one by one to obtain a block polymer.
Moreover, when the present invention is being carried out, one or more of the substituted epoxides can be used in combination with one or more of anionic-polymerizable monomers other than epoxides. These may be mixed at a time and used or may be introduced into the polymerization system one by one.
(3) Polyether
Examples of the polyether obtained in such a manner are as follows.
(3-1) Polyether represented by the formula (V): 
wherein
R5 represents a hydrocarbon group which has 8 to 50 carbon atoms and which may have a substituent, and
c represents a number being 150 and more on the average.
Here, the R5 is preferably an alkyl group or alkenyl group having 8 to 42 carbon atoms. When it has a substituent, the substituent is xe2x80x9cthe substituent of the present inventionxe2x80x9d. The c is preferably between 200 and 1,000,000.
(3-2) Polyether represented by the formula (VI): 
wherein
R6 represents a fluoroalkyl group having 2 to 30 carbon atoms,
J represents an alkylene group having 1 to 20 carbon atoms, and
d represents a number being 5 or more on the average.
Here, the R6group is preferably a perfluoroalkyl group, or a fluoroalkyl group having 4 to 12 carbon atoms, more preferably a perfluoroalkyl group having 4 to 12 carbon atoms. Further, a polyether wherein at least one terminal group of the R6 groups is a xe2x80x94CF2H group and the residue obtained by removing the xe2x80x94CF2H group from the R6 group is a perfluoroalkylene group is also exemplified as a preferable example. For example, it is an xcfx89H-perfluoroalkyl group having a hydrogen atom in its terminal.
The J is preferably an alkylene group having 1 to 5 carbon atoms, more preferably methylene group, ethylene group or trimethylene group. The d is preferably between 20 and 2,000,000, more preferably between 100 and 1,000,000.
(3-3) Polyether represented by the formula (VII): 
wherein
R4, G, b and p represent the mean as defined in the formula (IV) in the (1-3) term, and
e represents a number being 5 or more on the average.
Here, preferable examples of the R4, G, b and p include those described in the formula (IV) in the (1-3) term.
The e is preferably between 10 and 1,000,000.
(3-4) Polyether represented by the formula (VIII) 
wherein
X represents 
in which R5 represents the mean as defined in the formula (V) in the (3-1) term, R6 and J represent the mean as defined in the formula (VI) in the (3-2) term, and R4, G, b and p represent the mean as defined in the formula (IV) in the (1-3) term,
Y represents 
represents a group represented by X (provided that the case in which X and Y are same as each other is excluded), or represents a group originated from an anionic-polymerizable monomer other than the substituted epoxide, in which case Y may be plural types,
in which R7 represents a hydrocarbon group having 1 to 7 carbon atoms or represents a trialkyl (an alkyl group has 1 to 4 carbon atoms) silyl group,
R8 represents a hydrogen atom or represents a hydrocarbon group or halogen-substituted hydrocarbon group having 1 to 22 carbon atoms,
f represents a number being 150 or more when X is 
or represents a number being 5 or more when X is the other group, and
g represents a number being 5 or more.
Here, the group originated from the anionic-polymerizable monomer refers to a group originated from an anionic-polymerizable monomer being copolymerizable with the substituted epoxide in any of the (1-1) to (1-4) term of the 1st term.
The copolymer represented by the formula (VIII) is a system comprising two- or more-component. In the formula (VIII), X and Y may be a random type or may be a block type.
The f is preferably between 150 and 1,000,000 and the g is preferably between 10 and 1,000,000.